TYPO3 Core

Possible solution would be:

        if ($selectedFolder === false || $selectedFolder->getStorage()->isFallbackStorage()) {
            $selectedFolder = null;
        }

Patch set 2 for branch 11.5 of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/82999

Patch set 3 for branch 11.5 of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/82999

Hi Gernot,

The code in v11 is wrong and needs to be updated. Thanks for the report.
One question: Did you actually run into the exception in v11, or did you face the error in an ELTS instance and noticed that the coding mistake is available in v11 as well?

(I'm asking because I couldn't reproduce in v11)

Thanks, Benjamin

nevermind, found it: getSelectedFolder() return false if backend user has no "default" upload folder, which is the case when all storages are marked non-writable. With that the error is actually reproducible in v11 when trying to create a new file link.

Patch set 4 for branch 11.5 of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/82999